#include <iostream>
#include <tuple>
template <class T> void test(T value) {
  const int N = std::tuple_size_v<T>; // 编译器决定元素个数
  int a[N];
  std::cout << "当前输入的元素个数：" << N
            << " 获取 T 中元素个数（运行时获取）：" << std::tuple_size<T>{}
            << " 传入对象size = " << sizeof value << '\n'; // 3 3, 16
}

int main() { test(std::make_tuple(1, 2, 3.14)); }
